cmd/compile/internal/gc: remove dead code found by vet
cmd/compile/internal/gc: remove dead code found by vet

See report in commit 3c9fa388df826a67cb5042513e3df079709e6b8b.

Change-Id: I74a5995a1c1ca62b8d01857e89b084502e7da928
Reviewed-on: https://go-review.googlesource.com/14170
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Run-TryBot: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

roth1002/go,yangzhongj/go,ganboing/go-esx,greyhwndz/go,Samurais/go,skatsuta/go,xiuzhifu/go,albertjin/golang-go,polyverse-security/go,binarycrusader/go,joshsammut/go,mwhudson/go,GeorgiCodes/go,chinanjjohn2012/go,vanloswang/go,cyberroadie/go,fjballest/golang,arschles/go-1,myPublicGit/go,kakuhiroshi/go,ericsnowcurrently/go,josharian/go,arschles/golang-go,kakuhiroshi/go,4ad/go,ganboing/go-esx,arschles/golang-go,theass/go,ifagnosticism/go,binarycrusader/go,Jordanzuo/go,codestation/go,kim-racktop/go,jonasi/go,stormltf/go,kim-racktop/go,GeorgiCodes/go,rentongzhang/go,arschles/golang-go,yangzhongj/go,CiscoCloud/go,cloudflare/go,polyverse-security/go,vsdutka/go,nawawi/go,cyberroadie/go,honsiorovskyi/go,AALEKH/go,jefby/go,akutz/go,joshsammut/go,beealone/go,cookerzhu/go,jacobsa/go,mdp/go,yangzhongj/go,suncycheng/go,ImJasonH/go,likesea/go,Jordanzuo/go,dterei/go,arschles/go-1,cookerzhu/go,jacobsa/go,chinanjjohn2012/go,sndnvaps/go,ObjectiveJoe/go,vsdutka/go,devpadawan/go,golang/go,roth1002/go,arschles/golang-go,goodlang/good,ganboing/go-esx,AALEKH/go,suncycheng/go,slavau/go,greyhwndz/go,vanloswang/go,GeorgiCodes/go,slavau/go,CAFxX/go,devpadawan/go,4ad/go,goodlang/good,Badredapple/go,ichu501/go,dpatel06/go,kim-racktop/go,joshsammut/go,rachtsingh/gogojuice,jdhenke/go,honsiorovskyi/go,jefby/go,linux-on-ibm-z/go,Cofyc/go,cyberroadie/go,Samurais/go,Pulgafree/go,snowsnail/go,xujianhai/go,zhangg/go,roth1002/go,devpadawan/go,christopher-henderson/Go,deft-code/go,jacobsa/go,ichu501/go,suncycheng/go,jacobsa/go,zhangg/go,Badredapple/go,skatsuta/go,greyhwndz/go,gdey/go,cookerzhu/go,xujianhai/go,samanalysis/go,stormltf/go,xujianhai/go,theif519/go,b54898533/go,goodlang/good,arschles/go-1,albertjin/golang-go,jonasi/go,Jordanzuo/go,linux-on-ibm-z/go,myPublicGit/go,zhangg/go,rentongzhang/go,vsdutka/go,beealone/go,NunoEdgarGub1/go,honsiorovskyi/go,famorted/go,myPublicGit/go,goodlang/good,derekmarcotte/go,Badredapple/go,cloudflare/go,cloudflare/go,sndnvaps/go,fjballest/golang,momchil-velikov/go,linux-on-ibm-z/go,danielsoro/go,mikekap/go,binarycrusader/go,devpadawan/go,mdp/go,Samurais/go,Jordanzuo/go,roth1002/go,jonasi/go,mwhudson/go,famorted/go,slavau/go,rentongzhang/go,alex-zhang/go,honsiorovskyi/go,josharian/go,CAFxX/go,cookerzhu/go,akutz/go,skatsuta/go,codestation/go,polyverse-security/go,yasarkunduz/go,Samurais/go,Cofyc/go,mdp/go,malvira/go,samanalysis/go,xiuzhifu/go,vsekhar/elastic-go,rentongzhang/go,akutz/go,ganboing/go-esx,honsiorovskyi/go,AALEKH/go,alex-zhang/go,akutz/go,mwhudson/go,Cofyc/go,mdp/go,jacobhaven/go,famorted/go,zhangg/go,joshsammut/go,likesea/go,vsekhar/elastic-go,rachtsingh/gogojuice,Jordanzuo/go,suncycheng/go,GeorgiCodes/go,Badredapple/go,mgyenik/go,golang/go,mdp/go,snowsnail/go,fjballest/golang,nawawi/go,theass/go,gdey/go,4ad/go,alex-zhang/go,miolini/go,ifagnosticism/go,NunoEdgarGub1/go,dpatel06/go,kim-racktop/go,theass/go,rentongzhang/go,jdhenke/go,samanalysis/go,odeke-em/go,deft-code/go,b54898533/go,Badredapple/go,Pulgafree/go,Endika/go,yangzhongj/go,gdey/go,malvira/go,jdhenke/go,miolini/go,ganboing/go-esx,nawawi/go,skatsuta/go,mikekap/go,ericsnowcurrently/go,xujianhai/go,ImJasonH/go,likesea/go,josharian/go,vishsingh/go,jdhenke/go,kakuhiroshi/go,cloudflare/go,famorted/go,suncycheng/go,mikekap/go,yangzhongj/go,sndnvaps/go,ifagnosticism/go,ericsnowcurrently/go,codestation/go,vsekhar/elastic-go,nawawi/go,gdey/go,yasarkunduz/go,xiuzhifu/go,zhangg/go,Jordanzuo/go,myPublicGit/go,momchil-velikov/go,jacobsa/go,mgyenik/go,CiscoCloud/go,malvira/go,xiuzhifu/go,ifagnosticism/go,joshsammut/go,vsekhar/elastic-go,akutz/go,4ad/go,mgyenik/go,jacobhaven/go,yasarkunduz/go,rentongzhang/go,Badredapple/go,akutz/go,jacobsa/go,CiscoCloud/go,cookerzhu/go,alex-zhang/go,joshsammut/go,jacobhaven/go,ObjectiveJoe/go,miolini/go,albertjin/golang-go,alex-zhang/go,ImJasonH/go,arschles/golang-go,mwhudson/go,goodlang/good,dterei/go,stormltf/go,Jordanzuo/go,b54898533/go,jacobhaven/go,Endika/go,Pulgafree/go,kakuhiroshi/go,ichu501/go,dpatel06/go,ericsnowcurrently/go,malvira/go,jacobsa/go,cyberroadie/go,vanloswang/go,odeke-em/go,momchil-velikov/go,arschles/golang-go,chinanjjohn2012/go,greyhwndz/go,CiscoCloud/go,honsiorovskyi/go,yangzhongj/go,samanalysis/go,likesea/go,skatsuta/go,ericsnowcurrently/go,nawawi/go,kim-racktop/go,linux-on-ibm-z/go,roth1002/go,ObjectiveJoe/go,codestation/go,theif519/go,danielsoro/go,gdey/go,dpatel06/go,binarycrusader/go,mwhudson/go,samanalysis/go,jonasi/go,Endika/go,cookerzhu/go,4ad/go,CarterTsai/go,theass/go,odeke-em/go,stormltf/go,likesea/go,ericsnowcurrently/go,yasarkunduz/go,deft-code/go,samanalysis/go,kim-racktop/go,snowsnail/go,jonasi/go,jefby/go,mdp/go,codestation/go,jefby/go,skatsuta/go,skatsuta/go,devpadawan/go,CarterTsai/go,jefby/go,cyberroadie/go,goodlang/good,zhangg/go,Cofyc/go,rentongzhang/go,NunoEdgarGub1/go,GeorgiCodes/go,jdhenke/go,slavau/go,GeorgiCodes/go,CiscoCloud/go,CAFxX/go,jonasi/go,ImJasonH/go,nawawi/go,golang/go,snowsnail/go,vishsingh/go,vsekhar/elastic-go,albertjin/golang-go,cookerzhu/go,vishsingh/go,Pulgafree/go,vsdutka/go,kakuhiroshi/go,roth1002/go,vanloswang/go,dterei/go,ericsnowcurrently/go,xiuzhifu/go,famorted/go,myPublicGit/go,binarycrusader/go,kakuhiroshi/go,AALEKH/go,theass/go,honsiorovskyi/go,Samurais/go,mgyenik/go,theif519/go,mikekap/go,ifagnosticism/go,sndnvaps/go,ObjectiveJoe/go,beealone/go,xiuzhifu/go,derekmarcotte/go,kim-racktop/go,momchil-velikov/go,dterei/go,sndnvaps/go,linux-on-ibm-z/go,AALEKH/go,rachtsingh/gogojuice,GeorgiCodes/go,golang/go,ImJasonH/go,deft-code/go,odeke-em/go,myPublicGit/go,danielsoro/go,likesea/go,devpadawan/go,suncycheng/go,jacobsa/go,jdhenke/go,CiscoCloud/go,vsekhar/elastic-go,likesea/go,Pulgafree/go,josharian/go,momchil-velikov/go,alex-zhang/go,devpadawan/go,ichu501/go,deft-code/go,josharian/go,theass/go,Samurais/go,kim-racktop/go,zhangg/go,likesea/go,beealone/go,CarterTsai/go,derekmarcotte/go,stormltf/go,alex-zhang/go,mwhudson/go,Pulgafree/go,ganboing/go-esx,arschles/go-1,ichu501/go,vanloswang/go,mgyenik/go,NunoEdgarGub1/go,goodlang/good,rachtsingh/gogojuice,momchil-velikov/go,arschles/go-1,cloudflare/go,Endika/go,snowsnail/go,danielsoro/go,GeorgiCodes/go,samanalysis/go,AALEKH/go,dterei/go,deft-code/go,linux-on-ibm-z/go,greyhwndz/go,beealone/go,ichu501/go,mgyenik/go,fjballest/golang,jonasi/go,cyberroadie/go,zhangg/go,cyberroadie/go,jefby/go,deft-code/go,Cofyc/go,chinanjjohn2012/go,theif519/go,yasarkunduz/go,binarycrusader/go,yasarkunduz/go,b54898533/go,xiuzhifu/go,vsdutka/go,mikekap/go,rentongzhang/go,derekmarcotte/go,beealone/go,theif519/go,josharian/go,polyverse-security/go,yangzhongj/go,snowsnail/go,danielsoro/go,Badredapple/go,kakuhiroshi/go,fjballest/golang,ifagnosticism/go,4ad/go,derekmarcotte/go,greyhwndz/go,vsdutka/go,vishsingh/go,CAFxX/go,famorted/go,vsdutka/go,snowsnail/go,vishsingh/go,cloudflare/go,theif519/go,ObjectiveJoe/go,danielsoro/go,goodlang/good,NunoEdgarGub1/go,Endika/go,dterei/go,dterei/go,ImJasonH/go,ObjectiveJoe/go,vsekhar/elastic-go,ifagnosticism/go,yasarkunduz/go,CAFxX/go,jefby/go,xujianhai/go,dpatel06/go,xujianhai/go,mdp/go,gdey/go,Cofyc/go,samanalysis/go,snowsnail/go,akutz/go,b54898533/go,kakuhiroshi/go,chinanjjohn2012/go,cookerzhu/go,b54898533/go,vsdutka/go,nawawi/go,Samurais/go,ganboing/go-esx,4ad/go,fjballest/golang,myPublicGit/go,albertjin/golang-go,xiuzhifu/go,cloudflare/go,mgyenik/go,polyverse-security/go,dpatel06/go,chinanjjohn2012/go,mwhudson/go,b54898533/go,malvira/go,CarterTsai/go,polyverse-security/go,b54898533/go,albertjin/golang-go,Cofyc/go,binarycrusader/go,jonasi/go,AALEKH/go,CarterTsai/go,linux-on-ibm-z/go,theass/go,roth1002/go,beealone/go,albertjin/golang-go,arschles/golang-go,yasarkunduz/go,jdhenke/go,mikekap/go,sndnvaps/go,miolini/go,CarterTsai/go,fjballest/golang,slavau/go,miolini/go,derekmarcotte/go,rachtsingh/gogojuice,gdey/go,odeke-em/go,jacobhaven/go,Endika/go,jefby/go,CarterTsai/go,golang/go,roth1002/go,arschles/go-1,xujianhai/go,polyverse-security/go,rachtsingh/gogojuice,alex-zhang/go,CAFxX/go,vishsingh/go,NunoEdgarGub1/go,cloudflare/go,Pulgafree/go,stormltf/go,yangzhongj/go,devpadawan/go,jacobhaven/go,chinanjjohn2012/go,greyhwndz/go,fjballest/golang,CarterTsai/go,golang/go,slavau/go,vanloswang/go,suncycheng/go,mikekap/go,golang/go,josharian/go,greyhwndz/go,deft-code/go,theass/go,mdp/go,4ad/go,ImJasonH/go,golang/go,codestation/go,famorted/go,stormltf/go,momchil-velikov/go,ifagnosticism/go,malvira/go,dpatel06/go,NunoEdgarGub1/go,theif519/go,AALEKH/go,sndnvaps/go,miolini/go,xujianhai/go,myPublicGit/go,albertjin/golang-go,sndnvaps/go,famorted/go,dterei/go,slavau/go,Cofyc/go,CiscoCloud/go,Pulgafree/go,codestation/go,jacobhaven/go,jacobhaven/go,CAFxX/go,akutz/go,rachtsingh/gogojuice,arschles/go-1,linux-on-ibm-z/go,ichu501/go,danielsoro/go,ericsnowcurrently/go,vishsingh/go,Badredapple/go,Endika/go,ichu501/go,suncycheng/go,derekmarcotte/go,vanloswang/go,ObjectiveJoe/go,joshsammut/go,momchil-velikov/go,gdey/go,josharian/go,ImJasonH/go,beealone/go,vishsingh/go,CiscoCloud/go,skatsuta/go,nawawi/go,arschles/go-1,derekmarcotte/go,ganboing/go-esx,codestation/go,odeke-em/go,honsiorovskyi/go,mikekap/go,slavau/go,malvira/go,chinanjjohn2012/go,stormltf/go,mwhudson/go,dpatel06/go,vsekhar/elastic-go,mgyenik/go,joshsammut/go,danielsoro/go,jdhenke/go,binarycrusader/go,miolini/go,NunoEdgarGub1/go,malvira/go,odeke-em/go,Endika/go,Samurais/go,Jordanzuo/go,CAFxX/go,theif519/go,polyverse-security/go,odeke-em/go,cyberroadie/go,ObjectiveJoe/go,rachtsingh/gogojuice,miolini/go,vanloswang/go,arschles/golang-go